1. Field of the Invention
The present invention relates generally to an air-conditioner, more particularly, an air-conditioner having an improved air-mixing damper for modulating temperature of a discharged air into a passenger compartment.
2. Description of the Related Art
An automotive air-conditioner generally has an air-mixing damper as means for modulating temperature of an air discharged into a passenger compartment. An air-conditioner using a conventional air-mixing damper is shown in FIG. 8.
The air-conditioner comprises a duct 12 in which a fan 11 is accommodated. An evaporator 13 is disposed downstream of the fan 11 for cooling the air passing therethrough. A heater core 14 is disposed downstream of the evaporator 13 for heating the air passing therethrough. All the air from the fan 11 flows through the evaporator 13. However, the heater core 14 is so disposed in the duct 12 that a bypass passage 16 is defined between the heater core 14 and an inner wall of the duct 12. A heated air passage 15 is defined as a passage passing through the heater core 14. An air-mixing damper 17 having a holding shaft 18 is disposed at an edge of the heater core 14.
The holding shaft 18 is pivotally disposed in the duct 12 and at the boundary between the heated air passage 15 and the bypass passage 16.
The air-mixing damper 17 is controlled to rotate by the holding shaft 18.
The rotational movement of the air-mixing damper 17 varies an air-mixing ratio of a volume of the air flowing in the heated air passage 15 and a volume of the air flowing in the bypass passage 16.
For example, when the heated air passage 15 is blocked by the air-mixing damper 17, only a cooled air from the evaporator 13 is discharged into a passenger compartment (not shown), that is to say, it is in Max cooling Mode. Conversely when the bypass passage 16 is blocked by the air-mixing damper 17, only a heated air passing through the heater core 14 is discharged into the passenger compartment, that is to say, it is in Max Heat Mode.
The air-conditioner described above requires a large space, such as a semicircle with a radius of a length of the air mixing damper 17 so that a distance between the evaporator 13 and the heater core 14 is required more than the length of the air-mixing damper 17.
As a result, it is difficult to get a compact air-conditioner so as to install in a limited space of an automobile.
An improved air-conditioner is shown in Japanese Utility model laid-open publication No. 61-98609, which adopts a film damper as an air-mixing damper. The film damper has a width of as side as a half cross-sectional area of an air passage and is disposed downstream of an evaporator for blocking a half of an air-flow.
When the film damper is adopted in FIG. 8, the film damper is slidably moved in the air passage to selectively open and close a bypass passage 16 and a heated air passage 15 so that when the air-conditioner is operated in Bi-Level Mode, a half of a cross-sectional area of the air passage is always blocked by the film damper. It increases a resistance of an air-flow. Therefore, compared with the air-mixing damper 17 shown in FIG. 8, a volume of an air-flow is reduced in Bi-Level Mode.